1. Field of the Invention
The present invention relates to an ink jet recording material capable of recording ink images having a high color density, a high clarity, a high water-resistance, a high resistance to blotting of ink images due to a high humidity and optionally a high resistance to fading, and having a high surface smoothness and a high gloss. The ink jet recording material of the present invention enables sharp ink images, comparable to those of silver-salt photographic images, to be recorded thereon.
2. Description of the Related Art
The ink jet recording system is a system for recording ink images by jetting ink droplets, corresponding to images to be recorded, toward a recording medium to cause the jetted ink droplets to be directly absorbed, imagewise, into the recording medium.
An ink jet printer can easily effect multi-color recording on the recording medium and thus is now rapidly becoming popular, for home use and for office use, as a text- or picture-outputting machine for computers.
The multi-color recording system using the ink jet recording system can rapidly and accurately form complicated images and the quality (color density and clarity) of the recorded colored images is comparable to the quality of color images formed by a conventional printing system using a printing plate or by conventional color photography. In the case where the ink jet recording system is utilized for a small number of prints, the ink jet recording system is advantageous in that the cost for recording is lower than the printing cost of a conventional printing system or a conventional photographic printing system. The progress in the accuracy and color quality of the printer and an increase in the printing speed of the printer require the printing media to have an enhanced performance. High gloss is required and also, since the ink for the ink jet recording system contains a large amount of water or another liquid medium, particularly a liquid medium having a high boiling temperature to prevent a blocking of the ink jet nozzle heads and, after printing, the coloring material such as a dye exists together with the liquid medium for a long period in the recording layer, the conventional recording material is disadvantageous in that the ink images are blotted with the lapse of time and the stabilization of the color tone of the printed ink images is difficult.
To enhance the resistance of ink images printed on an image recording stratum to moisture, a plurality of attempts have been made. For example, in one attempt, a uniform aqueous solution or an emulsion latex of a cationic polymer is added to the ink or, in another attempt, fine solid particles having a cationic surface charge (for example, alumina particles or cation-modified silica particles are added to the ink.
For example, Japanese Unexamined Patent Publication No. 60-46,288 discloses an ink jet recording method using a recording material comprising an ink containing a specific dye and a polyamine, etc. Also, Japanese Unexamined Patent Publication No. 63-162,275 discloses an ink jet recording material comprising a cationic polymer and a cationic surfactant coated on or impregnated in a support. Further, use of fine inorganic cationic particles, for example, alumina or cation-modified silica particles is known, for example, from Japanese Examined Patent Publication No. 4-19,037 and Japanese Unexamined Patent Publication No. 11-198,520. The attempts mentioned above relatively greatly contributed to enhancing the water resistance of the printed ink images. However, the enhancing effect on the resistance to blotting of the ink images due to moisture is insufficient and, particularly, substantially no effect was found on stabilization of the color tone of the printed ink images within a short time.
To solve the above-mentioned problems, Japanese Unexamined Patent Publication No. 10-157,277 discloses an attempt in which a two-layered image recording stratum is formed on an opaque support, the opaqueness of an under layer is made higher than the opaqueness of the upper layer, and a white-coloring pigment is contained in the under layer. In this attempt, since the upper layer is formed transparent and the under layers is formed opaque, the portion of the dye of the ink absorbed in the under layer which dye may blot in the under layer, is hidden from sight in the opaque layer and thus cannot be recognized through the upper layer. In this attempt, a certain degree of effect is recognized, but the problems are not completely solved. Particularly, the dye absorbed and blotted in the under layer further spread into the upper layer with the lapse of time and as a final result, an ink image-blotting phenomenon appears. Also, by this attempt alone, it is difficult to stabilize the color tone of the printed ink images within a short time. Particularly, for a specific use in which the stabilization of the color tone within a short time is required, for example, the use of checking the color tone of ink images formed by an ink jet recording system for the purpose of proofreading of colored images of prints, the above-mentioned recording stratum is unsatisfactory.
Currently, since digital cameras have become popular and ink jet printers using a photo-ink, capable of recording images having a high accuracy and having a low price are available, a demand of recording material capable of recording thereon ink images having a high quality comparable to that of silver-salt photographic images is increased. Since the printers can record full-colored ink images at high speed with a high quality and accuracy, the recording material for the printers are also required to provide with further enhanced properties. Particularly, to use the ink jet recording system in place of the silver-salt photographic printing system, the ink jet recording materials are strongly required to have a high ink-absorbing rate, a high ink absorption capacity, a high roundness of dots, a high density of colored images, and high surface gloss and a smoothness comparable to those of silver salt photographic printing sheets.
To realize the high clarity and color density of the ink images comparable to the silver-salt photographic image, the inventors of the present invention provided, in Japanese Unexamined Patent Publication No. 9-286,165, an ink jet recording material having at least one ink receiving layer comprising fine silica particles having an average primary particle size of 3 to 40 nm and an average secondary particle size of 10 to 300 nm, and water-soluble resin. The fine silica particles contribute to enhancing the color-forming property of the ink and the clarity and brightness of the printed images.
Also, the use of the fine silica particles enables the printed images to exhibit a high color density and a high quality (clarity). However, since the silica particles exhibit an anionic property, the resultant images formed from a cationic dye ink exhibit an unsatisfactory water resistance. Also, a cationization treatment of silica particles is difficult. Further, the silica particle-containing recording stratum is disadvantageous in that the resultant smoothness and gloss thereof, without a gloss-providing treatment, are insufficient.
In another invention disclosed in Japanese Unexamined Patent Publication No. 10-193,776, an ink jet recording material having an ink-receiving and recording layer comprising fine silica particles having an average primary particle size of 20 xcexcm or less and a hydrophilic binder, is provided. Particularly, in this recording material, when fumed silica particles are used as the fine silica particles, a high gloss of the recording stratum can be obtained, and the ink exhibits a good color-forming property. However, the resultant gloss of the recording material is lower than that of the silver-salt photographic material. Also, the fumed silica particles are difficult to cationalization process. Further, the fumed silica particles are disadvantageous in that since the thixotropic property thereof is too high and thus the resultant coating liquid containing the fumed silica particles exhibits a poor stability in storage.
Currently, various types of ink jet recording materials containing alumina hydrate particles are provided. For example, Japanese Unexamined Patent Publication No. 8-324,098 discloses a process for producing an ink jet recording material in which a coating liquid containing alumina hydrate particles dispersed by high speed aqueous streams is employed. When the alumina hydrate particles dispersed by the high speed aqueous streams are employed, a recording stratum having a high transparency can be formed, but this recording stratum is disadvantageous in that the dispersion of the alumina hydrate particles causes the ink-absorbing property of the recording stratum to be decreased. Also, the alumina hydrate particle-containing recording stratum is unsatisfactory in the color-forming property of the dye in the ink and thus clear and sharp images cannot be obtained. A plurality of inventions relating to ink jet recording materials containing alumina hydrate particles having a boehmite structure are provided. The alumina hydrate particles having the boehmite structure exhibit a high laminating property and enable a recording stratum having a high gloss and a high smoothness to be obtained. Also, the resultant recording stratum exhibits a high transparency and the images printed on the recording stratum have a high color density. However, this type of recording stratum has a low ink absorption and thus is difficult to use practically. Also, the alumina hydrate particle-containing recording stratum has an insufficient color-forming property for the dye of the ink and thus clear and bright colored images are not obtained on the recording stratum.
Generally speaking, as a method of imparting a high gloss to a recording material, a method of smoothing a surface of a coating layer of the recording material by feeling the recording material to a smoothing apparatus, for example, a calender, and passing the recording material between a pair of pressing and heating rolls under pressure, is known. When only the above-mentioned conventional procedure is applied, the resultant gloss of the recording material is insufficient. Also, since the press-heating procedure causes the ink-absorbing pores formed in the coating layer to be decreased, as a result, the smoothed coating layer easily allows the printed ink images to be blotted. Particularly, in the current ink jet printing system, to form ink images having a photographic image-like tone but no roughened surface-like tone, printers having photoink-jetting nozzles through which low concentration ink images are superposed on each other are mainly used. Thus, the recording material is required to have a further enhanced ink absorption.
Various types of methods of forming an ink-receiving layer from an ink-absorbing polymeric material, for example, starch, gelatin, a water-soluble cellulose derivative, polyvinyl alcohol or polyvinyl pyrrolidone on a plastic film or a resin-coated paper sheet having a high gloss and a high smoothness, are known. The recording materials produced by the above-mentioned methods have a sufficiently high gloss. However, this type of recording materials exhibit a low ink absorption and a low ink-drying rate and, thus, the handling property of the recording material is insufficient, the ink is unevenly absorbed in the recording material, and the water-resistance and the resistance to curling of the recording material are insufficient.
As means for solving the above-mentioned problems, Japanese Unexamined Patent Publications No. 2-274,587, No. 8-67,064, No. 8-118,790, No. 9-286,162 and No. 10-217,601 disclose a coating layer containing, as a main component, super fine pigment particles. Among them, coating layers containing colloidal silica particles having a small particle size (disclosed in Japanese Unexamined Patent Publications No. 2-274,857, No. 8-67,064, and No. 8-118,790 have a high gloss and high water resistance. However, since the colloidal silica particles are primary particles independent from each other and thus fine pores for absorbing the ink cannot be formed between the particles, and the ink-absorbing properties of the coating layers are unsatisfactory for practical use.
Also, Japanese Unexamined Patent Publication No. 2-43,083 discloses a recording material having a surface layer comprising, as a main component, an aluminum oxide and an under layer having an ink absorbing property, as a recording material having a high resistance to fading of the recorded images, because the dye for the images is electrically bonded with the aluminum oxide particles and thus exhibits a high resistance to decomposition.
As mentioned above, the ink jet recording system in which an aqueous ink is jetted imagewise in the form of fine droplets through fine nozzles toward a recording material and ink images are formed on the surface of the recording material is advantageous in that the printing noise is low, full colored images can be easily formed, a high speed recording can be effected, and the recording cost is cheaper than that of other conventional recording systems. Thus, the ink jet recording system is widely employed as an output terminal printer, as a printer for facsimile machines plotters and as a printing system for notebooks, slips and tickets.
Due to the fact that the use of the printers is rapidly expanding, the accuracy and minuteness of the printed images have improved, the printing speed has increased and that digital cameras have been developed, the recording materials are required to have improved properties. Namely, a recording materials having a high ink-absorbing property, a high color density of recorded images, a high water resistance, a high light resistance, and a quality (clarity) and durability of the recorded images comparative to those of the silver-salt type photographic sheets, are in strong demand. Further, to obtain a photographic tone image, the recording material surface must have a high gloss.
As a recording sheet having a high surface gloss, a cast-coated paper sheet produced by contacting a wetted coating layer of the recording sheet with a mirror-finished peripheral surface of a heating drum under pressure, and drying the coating layer to transfer the mirror-like surface to the coating layer surface, is known. The cast-coated paper sheet has a higher surface gloss, a more superior surface smoothness, and a more excellent printing effect than those of the conventional super calender-finished coating sheet, and thus is mainly used for high quality prints. However, when the cast-coated paper sheet is used as an ink jet recording material, various problems occur.
Namely, the conventional cast-coated paper sheet generally exhibits a high gloss when the mirror-finished surface of the cast-coater drum is copied by the film-forming material, for example, a binder, contained in a pigment-containing composition from which the coating layer is formed. However, the film-forming material contained in the coating layer causes the porosity of the coating layer to be decreased or lost, and the ink-absorption of the coating layer when an ink jet recording procedure is applied thereof is significantly reduced. To improve the ink-absorption of the coating layer, it is important that a porous structure is formed in the cast-coating layer to cause the resultant coating layer to exhibit an enhanced ink-absorbing property. For this effect, it is necessary to decrease the film-forming property of the recording stratum. However, the decrease in the content of the film-forming material in the recording stratum creates a such a problem that the white sheet gloss of the resultant recording stratum decreases. As mentioned above, it was very difficult to simultaneously keep both the surface gloss and the ink jet recording property of the cast-coating layer at satisfactory levels.
As means for solving the above-mentioned problem, Japanese Unexamined Patent Publication No. 7-89,220 discloses that a cast-coated paper sheet having both excellent gloss and ink-absorbing property and thus useful for ink jet recording system can be produced by the steps of coating a coating liquid comprising, as a principal component, a composition of a copolymer having a gloss-transition temperature of 40xc2x0 C. or more on a paper sheet having a recording stratum comprising as principal components, a pigment and a binder, to form a coating layer for casting; and while the coating layer is kept in a wetted condition, bringing the wetted coating layer into contact with a heated casting surface of a casting drum under pressure, and then drying the coating layer to impart a high smoothness to the casting layer surface. Further, Japanese Unexamined Patent Publications No. 2-274,587 and No. 10-250,218 disclose a cast-coated recording stratum containing super-fine inorganic colloidal particles.
As mentioned above, currently, due to the development of high speed ink jet recording system, high accuracy and quality of the ink jet recorded images and full color recording system, on improvement in clarity, color density and storage durability of the recorded images is required of the ink jet recording material. For example, an ink jet recording material having a high recording quality and storage durability comparable to those of the silver-salt type photographic recording sheet is required. The above-mentioned prior art recording materials are insufficient to satisfy the above-mentioned requirements. Particularly, the conventional ink jet recording sheets having excellent gloss and a superior ink jet recording aptitude are not always satisfactory in resistance to fading of the printed ink images upon being exposed to sunlight or room light (for example, fluorescent lamp light). This problem has not yet been solved.
Regarding this problem, many attempts have been made to enhance the light resistance of the printed images by applying a light resistance-enhancing material to the ink jet recording sheets. For example, Japanese Unexamined Patent Publication No. 57-87,988 discloses an ink jet recording sheet containing, as at least one component, an ultraviolet ray-absorber. Japanese Unexamined Patent Publication No. 61-146,591 discloses an ink jet recording medium for recording colored images thereon with an aqueous ink containing a water-soluble dye, characterized in that the recording medium contains a hindered amine compound. Japanese Unexamined Patent Publication No. 4-201,594 discloses an ink jet recording material comprising a base material and an ink receiving layer formed on the base material and characterized in that the ink receiving layer contains super fine particulates of a transition metal compound. The recording materials mentioned above exhibit a certain light resistance-enhancing effect. However, they are insufficient in the ink-absorbing property and disadvantageous in that, with respect to the light resistance, the color balance of the faded images is unsatisfactory.
Japanese Unexamined Patent Publication No. 1-241,487 discloses an aqueous ink recording material having a coating formed on a base sheet surface and comprising 100 parts by weight of a resin binder comprising polyvinyl alcohol and a cationic, water-soluble resin and 0.1 to 30 parts by weight of a light-resistance-enhancing agent consisting of a compound having phenolic hydroxyl groups. This recording sheet is, however, unsatisfactory in the light resistance-enhancing effect thereof. Also, Japanese Unexamined Patent Publication No. 8-132,727 discloses an ink receiving layer comprising a metal complex of polyvinyl alcohol with calcium chloride, and Japanese Unexamined Patent Publication No. 9-290,556 discloses an ink jet recording sheet having a support and magnesium sulfate in a dry amount of 0.2 to 2.0 g/m2 attached to the support. The recording sheets mentioned above exhibit a relatively good color balance of faded colored images, but the retention in color density of the images after fading is insufficient, and thus these recording sheets are not usable in practice.
Japanese Unexamined Patent Publication No. 10-193,776 discloses an ink jet recording material characterized by containing at least one member selected from image-stabilizing agents and ultraviolet ray absorbers, as a fade-preventing agent. However, it was found that certain fade-preventing agents degrade the ink-absorbing property of the recording material, and generally, the light resistance of the resultant recording materials is insufficient.
Japanese Unexamined Patent Publications No. 11-20,306 and No. 11-192,777 respectively disclose an ink jet recording sheet having an ink receiving layer containing, as a cross-linking agent, boric acid or borax, for the purpose of enhancing the water resistance of the ink receiving layer. This type of ink receiving layer is not satisfactory in both gloss and light resistance. Japanese Unexamined Patent Publication No. 2000-73,296 discloses a paper sheet having a porous layer containing borax and thus exhibiting a decreased change in form (curling form) due to change in the environmental conditions. However, this type of the paper sheet is unsatisfactory in the gloss thereof.
Japanese Unexamined Patent Publication No. 11-263,065 discloses a mat-type ink jet recording sheet provided with an ink receiving layer comprising cyclodextrin, and thus has excellent reproducibility of dots, resolving power of images, color-reproducibility of images, color-forming property of ink and pigment ink-applicability. Also, Japanese Unexamined Patent Publication No. 11-286,172 discloses a recording sheet provided with an ink receiving layer containing cyclodextrin which causes the light resistance of the recorded images to be enhanced. However, the recording sheets mentioned above are unsatisfactory in the gloss thereof.
An object of the present invention is to provide an ink jet recording material capable of recording thereon ink images having excellent color density, clarity, water-resistance and resistance to blotting, and a superior sharpness comparable to that of silver-salt photographic images, and having high surface smoothness and gloss.
Another object of the present invention is to provide an ink jet recording material having a high gloss and excellent ink jet recording properties, such as color density and clarity of ink images, and capable of recording ink images having a high light-resistance.
The above-mentioned objects can be attained by the ink jet recording material of the present invention which comprises:
a substrate and an image-recording stratum, located on at least one surface of the substrate, formed from at least one ink receiving layer and comprising a binder and a plurality of pigment particles dispersed in the binder,
at least one ink receiving layer of the image-recording stratum comprising fine particles of at least one pigment selected from the group consisting of silica, aluminosilicate and xcex1-, xcex8-, xcex4- and xcex3-aluminas and having an average particle size of 1 xcexcm or less.
In the ink jet recording material of the present invention, preferably, at least one ink receiving layer of the image-recording stratum comprises fine particles of at least one silica compound selected from the group comprising silica and aluminosilicate and fine particles of at least one alumina compound selected from the group consisting of xcex1-, xcex8-, xcex4- and xcex3-aluminas, and the fine particles of the silica compound and the fine particles of the alumina compound respectively have an average particle size of 1 xcexcm or less.
In the ink jet recording material of the present invention, the fine particles of the alumina compounds are preferably in the form of secondary particles having an average secondary particle size of 500 nm or less, and consisting of a plurality of primary particles agglomerated with each other.
In the ink jet recording material of the present invention, the fine particles of the alumina compounds preferably have a BET specific area of 180 to 300 m2/g.
In the ink jet recording material of the present invention, the fine particles of the alumina compounds preferably have a BET specific area of 50 to 300 m2/g and a pore volume of 0.2 to 1.0 ml/g.
In the ink jet recording material of the present invention, the fine particles of the alumina compounds are preferably selected from rod-shaped fine particles of xcex4- and xcex3-aluminas having an average particle length of 300 nm or less.
In the ink jet recording material of the present invention, the fine particles of the alumina compounds are preferably a product of hydrolysis of an aluminum alkoxide and have an Al2O3 content of 99.99% by weight or more.
In the ink jet recording material of the present invention, the fine particles of the alumina compounds are preferably fine particles of fumed alumina.
In the ink jet recording material of the present invention, the fine particles of at least one silica compound selected from the group consisting of silica and aluminosilicate contained in the ink image-recording layer are preferably formed from an aqueous slurry containing secondary particles having a average secondary particle size of 500 nm or less, each of the secondary particles consisting of an agglomerate of a plurality of primary particles having an average primary particle size of 3 to 40 nm with each other.
In the ink jet recording material of the present invention, the fine particles of silica are preferably fine particles of fumed silica.
In the ink jet recording material of the present invention, preferably, the fine silica compound particles and the fine alumina compound particles are respectively products obtained by subjecting aqueous dispersions containing particles of materials for the silica compounds and the alumina compounds, to pulverization procedures using pulverization and dispersion means under pressure selected from homogenizers under pressure, ultrasonic homogenizers and high speed stream-impacting homogenizers, to such an extent that the pulverization products have an average particle size of 1 xcexcm or less.
In the ink jet recording material of the present invention, the image-recording stratum preferably has at least one ink receiving inside layer formed on the substrate and an ink receiving outermost layer formed on the outer surface of the ink receiving inside layer.
In the ink jet recording material of the present invention, the ink receiving inside layer of the image-recording stratum preferably contains fine particles of gel-method silica, and the ink receiving outermost layer preferably contains fine pigment particles of at least one member selected from the group consisting of the silica compounds and of the alumina compounds.
In the ink jet recording material of the present invention, the fine pigment particles contained in the ink receiving outermost layer are preferably secondary particles having an average secondary particle size of 800 nm or less and each consisting of a plurality of primary particles having an average primary particle size of 3 to 50 nm and agglomerated with each other to form secondary particles.
In the ink jet recording material of the present invention, the fine pigment particles contained in the ink receiving outermost layer are preferably fine fumed silica particles.
In the ink jet recording material of the present invention, the ink receiving outermost layer optionally further contains a cationic compound.
In the ink jet recording material of the present invention, the ink receiving outermost layer is preferably one formed by coating a coating liquid prepared by subjecting a mixture of the fine pigment particles and the cationic compound to a mechanical mix-dispersing procedure, on a substrate surface; and drying the coated coating liquid layer on the substrate surface.
In the ink jet recording material of the present invention, the fine silica particles contained in the ink receiving inside layers are preferably porous particles each having a plurality of fine pores having an average pore size of 20 nm or less.
In the ink jet recording material of the present invention, the substrate preferably exhibits a non-absorbing property for aqueous liquids.
In the ink jet recording material of the present invention, it is preferable that at least one ink receiving inside layer is formed from an aqueous coating liquid containing the fine pigment particles and a binder on the substrate; and the ink receiving outermost layer is formed from an aqueous coating liquid containing the fine pigment particles and binder on an outermost surface of the ink receiving inside layer,
the ink receiving outermost layer being formed in such a manner that the aqueous coating liquid for the ink receiving outermost layer is coated on the aqueous coating liquid layer for the ink receiving inside layer adjacent to the ink receiving outermost layer, before the aqueous coating liquid layer is dried, and the both the aqueous coating liquid strata for the ink receiving outermost layer and the ink receiving inside layer are simultaneously dried, to thereby enhance the ink image-receiving property and the surface smoothness of the image-recording stratum.
In the ink jet recording material of the present invention, the substrate is preferably formed from an air-impermeable material.
In the ink jet recording material of the present invention, the air-impermeable material for the substrate is preferably selected from laminate paper sheets comprising a support sheet consisting of a paper sheet and at least one air-impermeable coating layer formed on at least one surface of the support sheet and comprising a polyolefin resin.
In the ink jet recording material of the present invention, the ink receiving outermost layer optionally further comprises a cationic compound.
In the ink jet recording material of the present invention, the ink receiving outermost layer preferably exhibits a 75xc2x0 specular surface gloss of 30% or more.
In the ink jet recording material of the present invention, the ink receiving inside layer and the ink receiving outermost layer are preferably formed in such a manner that the coating procedure of the coating liquid for the ink receiving inside layer onto the substrate and the coating procedure of the coating liquid for the ink receiving outermost layer onto the adjacent ink receiving inside layer are substantially simultaneously carried out through a plurality of coating liquid-feeding slits of a multi-strata-coating apparatus.
In the ink jet recording material of the present invention, the simultaneous multi coating apparatus is preferably selected from multi coating slot die coaters, multi coating slide die coaters, and multi coating curtain die coaters.
In the ink jet recording material of the present invention, the ink receiving inside layer and the ink receiving outermost layer are preferably formed by such a manner that the coating procedure of the coating liquid for the ink receiving inside layer onto the substrate and the coating procedure of the coating liquid for the ink receiving outermost layer onto the adjacent ink receiving inside layer are successively carried out through a plurality of coating liquid-feeding slits of a plurality of coating apparatuses located independently from each other.
In the ink jet recording material of the present invention, the independent coating apparatuses are preferably selected from slot die coaters, slide die coaters and curtain die coaters each having a single coating liquid-feeding slit.
In the ink jet recording material of the present invention, the at least one ink receiving layer of the image-recording stratum comprising the binder and the fine pigment particle of at least one pigment selected from the group consisting of silica, aluminosilicate and xcex1-, xcex8-, xcex4- and xcex3-aluminas and having an average particle size of 1 xcexcm or less, optionally further comprises a light resistance-enhancing agent for images comprising at least one member selected from the group consisting of phenolic compounds, boric acid, borate salts and cyclodextrin compounds.
In the ink jet recording material of the present invention, it is preferable that the image-recording stratum comprises a plurality of ink receiving layers superposed on each other, that an ink receiving layer located outermost of the image-recording stratum comprises the fine pigment particles and the binder,
and that at least one ink receiving layer in the image-recording layer contains an image light resistance-enhancing agent comprising at least one member selected from the group consisting of phenolic compounds, boric acid, borate salts and cyclodextrin compounds.
In the ink jet recording material of the present invention, the fine pigment particles contained in the ink receiving layer containing the image light resistance-enhancing agent are preferably in the form of secondary particles having an average secondary particle size of 1 xcexcm or less and each consists of a plurality of primary particles having an average primary particle size of 3 to 40 nm agglomerated with each other.
In the ink jet recording material of the present invention, the phenolic compounds are preferably selected from the group consisting of hydroquinone compounds, pyrocatechol compounds and phenolsulfonic acid compounds.
In the ink jet recording material of the present invention, the cyclodextrin compounds are preferably selected from the group consisting of
xcex1-cyclodextrins,
xcex2-cyclodextrins,
xcex3-cyclodextrins,
alkylated cyclodextrins,
hydroxyalkylated cyclodextrins, and
cation-modified cyclodextrins.
In the ink jet recording material of the present invention, the cyclodextrin compounds are preferably xcex3-cyclodextrins.
In the ink jet recording material of the present invention, the image light resistance-enhancing agent is preferably contained in the ink receiving layer by coating the ink receiving layer with a solution of the image light resistance-enhancing agent and drying the coated solution.
In the ink jet recording material of the present invention, the content of the image light resistance enhancing agent in the ink receiving layer is preferably 0.1 to 10 g/m2.
In the ink jet recording material of the present invention, the fine pigment particles are preferably fine particles of at least one member selected from fumed silica, amorphous silica, aluminas and alumina hydrates.
In the ink jet recording material of the present invention, the fumed silica particles are preferably in the form of secondary particles having an average secondary particle size of 300 nm or less and each consisting of a plurality of primary particles having a primary particle size of 3 to 50 nm and agglomerated with each other.
In the ink jet recording material of the present invention, the ink receiving layer comprising the fine pigment particles and the binder optionally further comprises a cationic compound.
In the ink jet recording material of the present invention, the binder preferably comprises at least one member selected from the group consisting of water-soluble polymeric compounds, latices of copolymers of conjugated diene compounds, latices of vinyl copolymers, water-dispersible acrylic resins, water-dispersible polyester resins and water-dispersible polyurethane resins.
In the ink jet recording material of the present invention, the binder preferably comprises at least one member selected from the group consisting of polyvinyl alcohol, partially saponificated polyvinyl alcohols, acetacetylated polyvinyl alcohols, silyl-modified polyvinyl alcohols, cation-modified polyvinyl alcohols, and anion-modified polyvinyl alcohols.
In the ink jet recording material of the present invention, the substrate is preferably formed from a ink-nonabsorbing material.
In the ink jet recording material of the present invention, the surface of the image-recording stratum preferably has a 75xc2x0 specular gloss of 30% or more.